This invention relates generally to the field of printing utilizing ink jet technology, and more particularly to a method of utilizing a combination of ink jet technology and another printing technology that is not ink jet to print a composite image of a postage indicia image and another image with inks having distinct and unique characteristics.
Various details of the background of this invention are set forth in the Background of the Invention section of the aforementioned copending application, which section is hereby incorporated by reference and made a part of this application.
Briefly, the invention disclosed and claimed in that application is a method of printing a postage indicia image on an image receiving medium utilizing ink jet printing technology, the image being composed of discrete portions each of which is printed with an ink having a distinct and unique characteristic. The method comprises the steps of providing a pair of ink jet print heads, each print head having a linear array of ink jet nozzles, a reservoir for holding a supply of ink, and actuating means interposed between the array of nozzles and the reservoir for ejecting ink from the nozzles onto the image receiving medium in a predetermined image pattern. Ink is provided in each of the reservoirs having a different unique characteristic, and then causing relative movement between the image receiving medium and the print heads. Finally, each of the actuating means is activated simultaneously during a single pass of the relative movement between the image receiving medium and the print heads so that ink from each of the print heads is deposited on the image receiving medium during the single pass in a predetermined sequence of operation for each print head, with the result that one portion of the image is printed with ink having a certain unique characteristic and simultaneously another portion of the image is printed with ink having a different unique characteristic.
In the postage indicia image printed by that method, one of the discrete portions is composed of alpha-numeric data which must be machine readable, and therefor must be printed with a clean, high quality ink that has a high degree of water fastness so that it will not smear if it is somehow exposed to excessive moisture. The other discrete portion is composed of graphic material which need not be machine readable and therefore need not be printed with water fast ink, but which must contain a fluorescent material that can be detected by a suitable fluorescent material detecting device so that the orientation of an envelope passing through a facing machine, as explained in the aforementioned Background of the Invention section of the copending application, can be detected and recognized as proper or improper so that it can be passed on or reoriented, as the case may be.
One disadvantage of this printing method is that the actual embodiment required to carry out the invention required at least two entire ink jet printing devices, one for each of the discrete portions, and each with its own one or two linear arrays of nozzles, depending on the height of the individual discrete portions, its own ink reservoirs and its own actuating means for ejecting minute droplets of ink from the nozzles onto the image receiving medium. In other words, in order to print both the graphic portion of the postage indicia of that application with the ink having the distinct characteristics required for each of the indicia portions, a complete duplication of the ink jet printing devices is required.
Another disadvantage is that each ink jet printing device requires a unique form of ink, in that the conventional ink used in current postage meter indicia printing devices does not work in printers using ink jet technology, thereby requiring custom made inks adapted from similar inks developed for other purposes. Thus, for the alpha-numeric portion of the indicia, an ink is required that is water based for many ink jet printing devices, such as bubble jet. Also it must be sufficiently water fast to meet the standards of the Postal Service for water fastness, and typically water based inks are not as water fast as solvent based inks, but the latter cannot be used in bubble jet printing devices because they are not compatible. For the graphic portion of the indicia, an ink is required that has a fluorescent material therein, but it must still be water based, although it need not be water fast. Typically, the inks used in conventional postage meters are oil based and are both water fast and have fluorescent material therein.
Thus, the complete duplication of all of the components and individual parts of the ink jet print heads involves a degree of complexity, cost and maintenance which tends to offset the savings in complexity and cost of the ink jet printing device over conventional postage meter indicia printing devices.
The present invention at least obviates if not entirely eliminates the disadvantages and drawbacks of the invention disclosed and claimed in the aforementioned copending application. This application discloses and claims an invention that avoids the complete duplication of ink jet print heads described above, and instead utilizes ink jet technology to print an entire postage indicia consisting of both machine readable alpha-numeric data, and a non-machine readable graphic element which makes up part of the postage indicia, and utilizes conventional, non-ink jet technology for a suitable device to print a mere non-distinct graphic image with any conventional fluorescent, non-water fast ink, solely for the purpose of having a fluorescence recognizable portion of any convenient design adjacent to the postage indicia.
Thus, in its broader aspects, the present invention is a method of printing a composite image composed of a postage indicia image and an adjacent nondescript image on an image receiving medium utilizing a combination of ink jet printing technology for the postage indicia image and a printing technology other than ink jet for the nondescript image, the postage indicia image and the nondescript image being printed by separate printing devices having different inks, each having a distinct and unique characteristic. In this environment, the method of the invention comprises the steps of providing a pair of printing devices, one of which incorporates ink jet technology and includes an ink jet print head having an array of ink jet nozzles, a reservoir for holding a supply of ink, and actuating means interposed between the array of nozzles and the reservoir for ejecting ink from the nozzles in a predetermined image pattern, the other of which printing devices incorporates a non-ink jet printing technology. Ink is provided to each of the printing devices having a different unique characteristic, and then causing relative movement between the image receiving medium and the ink jet printing device and the other printing device. Finally, the actuating means of the ink jet print head and the other printing device are actuated simultaneously during a single pass of the relative movement between the image receiving medium and the print head of the ink jet printing device and the other printing device, so that ink from the ink jet printing device and from the other printing device is deposited on the image receiving medium during the single pass in a predetermined sequence of operation for the ink jet print head and the other printing device, with the result that the postage indicia image is printed with ink having a certain unique characteristic and simultaneously the nondescript image is printed with ink having a different unique characteristic.
In some of its more limited aspects, the linear array of nozzles of the ink jet print head and the other printing device are arranged in side by side relationship so that the other printing device prints the nondescript image immediately adjacent to the postage indicia image. The step of causing the relative movement includes the step of maintaining the printing devices stationary and causing the image receiving medium to move past the printing devices.
Having briefly described the general nature of the present invention, it is a principal object thereof to provide a method of printing a composite image composed of a postage indicia image and an adjacent nondescript image on an image receiving medium utilizing a combination of ink jet printing technology for the postage indicia image and a printing technology other than ink jet for the nondescript image.
It is another object of the present invention to provide a method of printing a combination image composed of a postage indicia image and an adjacent nondescript image on an image receiving medium in which both portions of the composite image are printed with inks having unique characteristics, the ink for the postage indicia image being water fast and the ink for the nondescript image being fluorescent and somewhat water fast.
These and other advantages and features of the present invention will become more apparent from an understanding of the following detailed description of a presently preferred embodiment of the present invention, when considered in conjunction with the accompanying drawing.